Optical module and observation device

Abstract

An optical module ( 1 A) includes a polarization beam splitter ( 10 A) having a light splitting surface ( 11 ), polarization elements ( 20, 40 ), and respectively arranged on an optical path of a first polarization component (L 2 ) transmitted through the light splitting surface ( 11 ) and an optical path of a second polarization component (L 4 ) reflected by the light splitting surface ( 11 ), a reflective SLM ( 30 ) that modulates and reflects the first polarization component (L 2 ) passing through the polarization element ( 20 ), and a reflective SLM ( 50 ) that modulates and reflects the second polarization component (L 4 ) passing through the polarization element ( 40 ). The first modulation light (L 3 ) passing through the polarization element ( 20 ) again and then reflected by the light splitting surface ( 11 ) and the second modulation light (L 5 ) passing through the polarization element ( 40 ) again and then transmitted through the light splitting surface ( 11 ) are combined with each other.

The invention claimed is: 
     
       1. An optical module comprising:
 a polarization beam splitter including a light splitting surface configured to reflect an s-polarization component included in input light and transmit a p-polarization component; 
 a first polarization element including a Faraday rotator arranged on an optical path of a first polarization component in the input light transmitted through the light splitting surface and configured to rotate a polarization plane of the first polarization component; 
 a first reflective spatial light modulator configured to modulate the first polarization component passing through the first polarization element to generate first modulation light, and reflect the first modulation light to the first polarization element; 
 a second polarization element including a Faraday rotator arranged on an optical path of a second polarization component in the input light reflected by the light splitting surface and configured to rotate a polarization plane of the second polarization component; and 
 a second reflective spatial light modulator configured to modulate the second polarization component passing through the second polarization element to generate second modulation light, and reflect the second modulation light to the second polarization element, 
 wherein the first modulation light passing through the first polarization element and then reflected by the light splitting surface and the second modulation light passing through the second polarization element and then transmitted through the light splitting surface are combined with each other and output from the polarization beam splitter, 
 wherein the polarization plane of the first polarization component before modulation may be rotated 45° by the first polarization element, and a polarization plane of the first modulation light after modulation may be further rotated 45° by the first polarization element, and 
 wherein the polarization plane of the second polarization component before modulation may be rotated 45° by the second polarization element, and a polarization plane of the second modulation light after modulation may be further rotated 45° by the second polarization element. 
 
     
     
       2. The optical module according to  claim 1 ,
 wherein the first and second reflective spatial light modulators are liquid crystal types, and 
 an alignment direction of liquid crystal of the first reflective spatial light modulator and an alignment direction of liquid crystal of the second reflective spatial light modulator are orthogonal to each other. 
 
     
     
       3. The optical module according to  claim 1 , further comprising:
 a polarization element arranged on an optical path between the polarization beam splitter and the first reflective spatial light modulator or on an optical path between the polarization beam splitter and the second reflective spatial light modulator, 
 wherein the polarization element is either the first polarization element or the second polarization element. 
 
     
     
       4. An observation apparatus, comprising:
 the optical module according to  claim 1 ; 
 a gathering optical system configured to gather an observation light from the observation target and cause the observation light to be input as the input light to the optical module; 
 an image-forming optical system configured to form an image of light output from the optical module; and 
 a photodetector configured to detect light from which the image has been formed by the image-forming optical system. 
 
     
     
       5. The observation apparatus according to  claim 4 ,
 further comprising: 
 a pinhole arranged on an optical path between the image-forming optical system and the photodetector.